Rick McGuire wrote:
The more the geronimo javamail support is starting to get used, the
more uncomfortable I'm getting with the current structure of the
javamail code. Let me level-set the situation first, so everybody
understands the issues.
To start with, the Sun impl of javamail is not really like other jar
files we consider "spec" code. This jar files contains lots of
classes in the javax.mail.* package tree, but it also contains a
number of backing classes in a com.sun.mail.* tree that help implement
certain features. For example, there are various encoders/decoders
used by the MimeUtility class. These classes are undocumented, and
are separate from the public javamail api classes.
In addition to those classes, the Sun javamail jar file contains the
Sun implementations of the protocol transports and stores (smtp, pop3,
and imap are supported). In order to use the Sun version of javamail,
you only need to javamail jar and the jaf (activation jar).
For the Geronimo implementation, things are split up a little more.
The geronimo-spec-javamail jar file contains all of the javax.mail.*
classes, plus whatever backing utility classes are needed to implement
some of the features (with org.apache.geronimo.* package structure).
The jar does NOT however, contain any of the protocol implementations.
The Geronimo protocol implementations are contained in the
javamail-transport module of the main Geronimo code tree. This jar
contains only the protocol implementations, plus some utility classes
shared between the protocols. In order to use the Geronimo javamail
support, you need 3 jar files: 1) the activation jar, 2) the
javamail jar, and 3) the javamail-transport jar. 1) and 2) are
available separately, but 3) IIUC, is only available within a Geronimo
snapshot jar.
And just to confuse matters even more, there is another Geronimo mail
module. This module contains GBeans for configuring various mail
resources. These GBeans are independent of which javamail
implementation is being used, so we can keep these out of the discussion.
This is normal for just about all the spec implementations for
Geronimo. 1) spec jar, 2) impl, 3) GBean-mumbo-jumbo. Hopefully, w/
XBean, the GBean stuff will go away.
There is a major problem with the current Geronimo structure. The
implementation of the protocol handlers (transports and stores) is
highly dependent on the version of the api they are written to. I ran
into this problem just today. Jira GERONIMO-1957 addressed the fact
that changes in the geronimo 1.1 javamail spec jar broke the 1.0
version of the SMTP transport. However, the current 1.1 codebase was
running with this obsolete code, so I had to back port the trunk
version of the SMTP transport into the 1.1 code tree. This also
raised the question of whether we should pull back the other
transport/store implementations into 1.1.
Now this is an issue that never arises with the Sun implementation.
Since the protocol handlers are contained within the API jar, you can
never get these packages out of sync. They travel around together by
definition. In order for somebody to make use of the Geronimo
javamail stack, you'd need to pull down the javamail and activation
spec jars, then extract a javamail-transport jar from a Geronimo
snapshot that was using a matching spec level. Lots of opportunity
for error here, and it makes it difficult for other projects to use
the javamail support. Axis is already doing this, but fortunately,
they are only using the javax.mail.* stuff for Mime encoding support
and are not dependent on transport or store implementations.
It seems, at a minimum, that the javamail-transport code should be
moved from being a Geronimo module to a spec component. Ideally, it
really should be merged into the javamail spec module to mirror how
the Sun implementation works.
Am I missing something? Is there some compelling reason why this
should be structured this way? I really suspect we ended up at this
point through a combination of ignorance and historical accident.
Originally, the smtp transport code was just a sandbox component. It
was upgraded into working code because the console wanted to implement
a portlet for configuring mail resouces configurations. When this
code was promoted out of the sandbox, a new javamail-transport module
was created because we weren't really sure where it really
belonged....and we named it badly to boot. It really should have been
called javamail-protocol. The transport portion of the name starting
looking silly when we add the pop3 STORE protocol handler.
I look at things from a different viewpoint. I never really understood
why any part of the implementation had to be bundled with the JavaMail
spec jar. Folklore has it that the specification implies that this must
be the case. This flies in the face of my experience w/ many of the
Java JSR specs that I am familiar with; I have not read the spec for
fear of being asked to support it. :) IMO, doing something because Sun
does it that way is not a good argument.
Can you explain why *any* part of the implementation needs to be a part
of the spec jar? My personal preference is to keep the protocol
handlers out of it.
Regards,
Alan
